New study shows honeybees harmed by herbicide used on GMO crops

http://www.gmwatch.org/index.php/news/archive/2014/15710-new-
study-shows-honeybees-harmed-by-herbicide-used-on-gmo-crops

21 October 2014.

Glyphosate herbicide can disrupt learning behaviour in honeybees and severely impair long-term colony performance

EXCERPT: The scientists who conducted the new study used field-realistic levels of glyphosate, similar to what honeybees may encounter on a farm growing GMOs. They found that learning behavior and short-term memory retention decreased significantly compared with the control groups.

1. New study shows honeybees harmed by herbicide used on GMO crops
2. Effects of field-realistic doses of glyphosate on honeybee appetitive behaviour

1. New study shows honeybees harmed by herbicide used on GMO crops

Judson Parker
examiner.com, 15 Oct 2014
http://www.examiner.com/article/new-study-shows-honeybees-harmed-
by-herbicide-used-on-gmo-crops

One of every three bites of food we eat is from a crop pollinated by honeybees.

2. Effects of field-realistic doses of glyphosate on honeybee appetitive behaviour

Herbert LT, Vázquez DE, Arenas A, Farina WM
J Exp Biol. 2014 Oct 1;217(Pt 19):3457-64. doi: 10.1242/jeb.109520. Epub 2014 Jul 25.
http://www.ncbi.nlm.nih.gov/pubmed/25063858

Abstract

Glyphosate (GLY) is a broad-spectrum herbicide used for weed control. The sub-lethal impact of GLY on non-target organisms such as insect pollinators has not yet been evaluated. Apis mellifera is the main pollinator in agricultural environments and is a well-known model for behavioural research. Honeybees are also accurate biosensors of environmental pollutants and their appetitive behavioural response is a suitable tool with which to test sub-lethal effects of agrochemicals. We studied the effects of field-realistic doses of GLY on honeybees exposed chronically or acutely to the herbicide. We focused on sucrose sensitivity, elemental and non-elemental associative olfactory conditioning of the proboscis extension response (PER), and foraging-related behaviour. We found a reduced sensitivity to sucrose and learning performance for the groups chronically exposed to GLY concentrations within the range of recommended doses. When olfactory PER conditioning was performed with sucrose reward with the same GLY concentrations (acute exposure), elemental learning and short-term memory retention decreased significantly compared with controls. Non-elemental associative learning was also impaired by an acute exposure to GLY traces. Altogether, these results imply that GLY at concentrations found in agro-ecosystems as a result of standard spraying can reduce sensitivity to nectar reward and impair associative learning in honeybees. However, no effect on foraging-related behaviour was found. Therefore, we speculate that successful forager bees could become a source of constant inflow of nectar with GLY traces that could then be distributed among nestmates, stored in the hive and have long-term negative consequences on colony performance.